Various embodiments of a seat track mechanism are described herein. In particular, the embodiments described herein relate to an improved positively engaged locking (PEL) system or mechanism for a vehicle. Vehicles commonly include seats that are movably mounted on a vehicle floor to provide an adjustable position of the seat relative to the vehicle floor in a fore and aft direction. For example, the occupant of the driver's seat may want to adjust his or her position relative to the steering wheel and brake and accelerator pedals. The vehicle seat may be mounted on tracks for slidably moving the seat in the fore and aft direction along the vehicle floor. Commonly, a pair of track assemblies is mounted on the underside of the seat between the vehicle floor and the seat bottom. One track assembly is generally mounted on the inboard side of the seat, and the other track assembly is generally mounted on the outboard side of the seat. A typical track assembly includes a lower track bolted to the vehicle floor. An upper track is mounted on the seat. The upper track is slidably mounted on the lower track. Ball or roller bearings are commonly provided between portions of the tracks for ease of moving the upper track relative to the lower track.
The track assemblies include a locking assembly which prevents the tracks from moving relative to one another during normal usage of the seat. When the user wants to move the seat position, the user actuates the locking assembly to an unlatched position, thereby permitting the seat to be moved to a desired position. After the seat is in its desired position, the user then actuates the locking assembly to its latched position, thereby preventing the seat from moving relative to the floor. U.S. Pat. Nos. 6,874,747 and 7,191,995 illustrate examples of known track assemblies which use an actuating mechanism mounted on the outside of the tracks for moving engagement pins into and out of openings formed in the tracks to provide for locked and unlocked conditions. Such track assemblies may require clearance and spacing adjacent the actuating mechanism to prevent obstruction of the operation of the track assembly. U.S. Pat. No. 6,637,712 illustrates an example of a known track mechanism that uses pins slidably mounted in a vertical orientation wherein the pins extend underneath the tracks when in their locked position. Such a track assemblies may require clearance from the vehicle floor to operate and is susceptible to obstruction hindering the operation of the track assembly.